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seems to me conclusive against the cerebral origin of the symptom, for it is not in the stage of general muscular excitement, when the pneumogastric clearly is under excitation, that the symptom is demonstrated, but at the stage when the cerebrum is practically dead, when the muscles which are under cerebral and spinal influence are dead, and when nothing lives except the cardiac ganglia, and their reserve, the sympathetic cardiac ganglia.
(5) Further, the same experiment differentiates between the action of the sympathetic cardiac ganglia, and the true cardiac ganglia ; for when the sympathetic fails in function, and intermittent action is developed, the cardiac centres still sustain a feeble action, even when all other nervous communication is cut off. Hence the failure does not lie in the true cardiac centres.
(6) The last reason for a modification of view respecting the seat of nervous lesion in cases of intermittency of the pulse, is the strength of the proposition that the centres of the great ganglionic system are either the distinct centres of the emotional faculties, or that there is a direct connection between the sensorial organs and the sympathetic, so that emotions received through the senses are at once transmitted to the organic centres. It was demonstrated many years ago by the distinguished physiologist, Dr. Wilson Philip, that the ganglionic system can be excited to action through the sensorial organs without exciting the muscles called voluntary; and that when an impression which excites us involuntarily is received by the senses, it must pass through the involuntary nervous system to the involuntary muscles. Thus, change in the centres of the involuntary nervous chain may be excited by what is called mental impression, and central function may be destroyed as easily by such an impression as by a physical injury.
I look at the diagram of the organic nervous system, and see there depicted the emotional brain. If we could put the organic
ganglia and their nervous filaments, as a distinct system, side by side with the cerebro-spinal system, we should probably discern a system as extensive as the cerebro-spinal itself, the centres of which, subject to certain voluntary control, condense and regulate the force which is expended on instinctive and involuntary action.
In simple truth, every human possesses two nervous natures. The one primitive, impulsive, instinctive, propelling, sustaining, and probably capable of no immediate or direct education; a nature seated in the ganglionic centres. The other secondary, receptive, directing, controlling, and susceptible of direct education; a nature seated in the cerebro-spinal centres.
We are all conscious of these two natures. We laugh, or cry, or move, instinctively, at something that affects or influences our organic system, and we control ourselves by an act of reason, or in other words an act of brain, and we say the thing was worth laughing at, or crying at, or moving for, or it was not worth it, as we say of a commodity we have bought, it was, or it was not worth what we gave for it. Thus, like the centrifugal and centripetal forces, the two forces in our body act, the one in subjection to the other; and if in any given case the emotional centres were to be excited to such degree that the controlling or cerebro-spinal organs lost their power, I see no reason why a person should not laugh, or cry, or move, under emotional impulse, until he died. In hysteria we see the effect of emotional impulse carried a long way towards death ; in the dancing mania of the middle ages it was carried, in hundreds of cases, to the actual catastrophe of death.
And what is more, we are not only conscious of the two natures, but we refer the emotional nature to its true seat. We say of sorrow, “it sits beavy on the heart,” and the glow of pleasure, or the gust of fear, are each immediately conveyed to us by sensations distinctly referable to the organic nervous centres, not to the reasoning brain, which at once endeavours